…Officers wrote that they knew from their training and work experience that the foot-tapping was a signal used by people looking for sex.
…
After a man in the adjacent stall left, Craig entered it and put his luggage against the front of the stall door, “which Sgt. Karsnia’s experience has indicated is used to attempt to conceal sexual conduct by blocking the view from the front of the stall,” said the complaint.

The complaint said Craig then tapped his right foot several times and moved it closer to Karsnia’s stall and then moved it to where it touched Karsnia’s foot. Karsnia recognized that “as a signal often used by persons communicating a desire to engage in sexual conduct,” the complaint said.

Assuming this is true (and recalling humorous-in-retrospect documents that we’ve all seen about law enforcement deconstructing hippies, punks, heavy metal, gangs, etc., it very way may not be), it’s cool to consider a signal that can only be interpreted by those that know what it means. To everyone else, it may not even penetrate your awareness. Until the communication is decoded, it’s almost perfect, especially for messages that may be risky.

I’m fascinated to consider that (maybe, just maybe) someone may have at some point tapped at me, and I wouldn’t have necessarily noticed and certainly not interpreted it as it’s presumably intended.